/**
 * @author qiao / https://github.com/qiao
 * @author mrdoob / http://mrdoob.com
 * @author alteredq / http://alteredqualia.com/
 * @author WestLangley / http://github.com/WestLangley
 * @author erich666 / http://erichaines.com
 */

// This set of controls performs orbiting, dollying (zooming), and panning.
// Unlike TrackballControls, it maintains the "up" direction object.up (+Y by default).
//
//    Orbit - left mouse / touch: one-finger move
//    Zoom - middle mouse, or mousewheel / touch: two-finger spread or squish
//    Pan - right mouse, or arrow keys / touch: two-finger move



THREE.OrbitControls = function ( object, domElement ) {
    // object：指定相机对象，比如多个相机对象(场景相机对象、UI相机对象)，只有一个起作用
    
        this.object = object;
        // domElement:指定鼠标事件起作用的范围，默认是整个document，所有html元素
        // 比如3D建模软件，可以把范围指定为renderer.domElement，渲染器引用render的domElement属性引用指向绘图区canvas
        this.domElement = ( domElement !== undefined ) ? domElement : document;
    
        // Set to false to disable this control
        // 设置为false以禁用此控件
        this.enabled = true;
    
        // "target" sets the location of focus, where the object orbits around
        // "target"设置对象绕过的焦点位置
        // 与lookAt相关：.lookAt( scope.target );   视角绕着谁旋转
        // 平移之后，旋转中心仍然是默认的原点，是否可以以鼠标为中心
        // 缩放的中心也是原点   能不能也改成以鼠标为中心
        // 任何时候都以鼠标为中心进行旋转、缩放、平移
        this.target = new THREE.Vector3();
    
        // How far you can dolly in and out ( PerspectiveCamera only )
        // 您可以进出多远（仅限PerspectiveCamera）
        this.minDistance = 0;
        this.maxDistance = Infinity;
    
        // How far you can zoom in and out ( OrthographicCamera only )
        // 您可以放大或缩小多少（仅限OrthographicCamera）
        // 相对你原来设置相机视觉效果  设置缩放倍数
        // 比如商品展示  0.5~2之间
        this.minZoom = 0;
        this.maxZoom = Infinity;
    
        // How far you can orbit vertically, upper and lower limits.
        // Range is 0 to Math.PI radians.
        //你可以垂直绕行多远，上限和下限。
    //范围从0到Math.PI弧度。
        // 上下旋转范围
        this.minPolarAngle = 0; // radians
        this.maxPolarAngle = Math.PI; // radians
    
        // How far you can orbit horizontally, upper and lower limits.
        // If set, must be a sub-interval of the interval [ - Math.PI, Math.PI ].
        //你可以绕水平方向运行多远，上限和下限。
        //如果设置，则必须是区间[ - Math.PI，Math.PI]的子区间。
    
        // 左右旋转范围
        this.minAzimuthAngle = - Infinity; // radians
        this.maxAzimuthAngle = Infinity; // radians
    
        // Set to true to enable damping (inertia)
        // If damping is enabled, you must call controls.update() in your animation loop
        //设置为true以启用阻尼（惯性）
        //如果启用阻尼，则必须在动画循环中调用controls.update（）
        this.enableDamping = false;
        this.dampingFactor = 0.25;
    
        // This option actually enables dollying in and out; left as "zoom" for backwards compatibility.
        // Set to false to disable zooming
        //这个选项实际上可以使进出进入; 为了向后兼容，保留为“缩放”。
    //设置为false以禁用缩放
        this.enableZoom = true;
        this.zoomSpeed = 1.0;
    
        // Set to false to disable rotating
        //设置为false以禁用旋转
        this.enableRotate = true;
        this.rotateSpeed = 1.0;
    
        // Set to false to disable panning平移
        this.enablePan = true;
        this.panSpeed = 1.0;
        // 如果为true，则在屏幕空间中平移
        this.screenSpacePanning = false; // if true, pan in screen-space
        this.keyPanSpeed = 7.0;	// pixels moved per arrow key push 像素按箭头键移动
    
        // Set to true to automatically rotate around the target
        // If auto-rotate is enabled, you must call controls.update() in your animation loop
        //设置为true以自动围绕目标旋转
    //如果启用自动旋转，则必须在动画循环中调用controls.update（）
        this.autoRotate = false;
        // 当fps是60时，每轮30秒
        this.autoRotateSpeed = 2.0; // 30 seconds per round when fps is 60
    
        // Set to false to disable use of the keys禁用键使用
        this.enableKeys = true;
    
        // The four arrow keys  四个箭头键
        this.keys = { LEFT: 37, UP: 38, RIGHT: 39, BOTTOM: 40 };
    
        // Mouse buttons
        // orbit：轨道    ZOOM：放大   pan对应平移
        // 给特定的键命名
        this.mouseButtons = { ORBIT: THREE.MOUSE.LEFT, ZOOM: THREE.MOUSE.MIDDLE, PAN: THREE.MOUSE.RIGHT };
    
        // for reset  用于复位、重置
        this.target0 = this.target.clone();
        this.position0 = this.object.position.clone();
        this.zoom0 = this.object.zoom;
    
        //
        // public methods
        //
    // getPolarAngle获得极化角    Polar：极地的
        this.getPolarAngle = function () {
    // phi：表示希腊文的第21个字母，角度φ
    // spherical：球形的
            return spherical.phi;
    
        };
    // Azimuthal：方位角
        this.getAzimuthalAngle = function () {
    
            return spherical.theta;
    
        };
    // 记录目标点、相机位置、相机缩放状态
        this.saveState = function () {
    
            scope.target0.copy( scope.target );
            scope.position0.copy( scope.object.position );
            scope.zoom0 = scope.object.zoom;
    
        };
    // 重置
        this.reset = function () {
    
            scope.target.copy( scope.target0 );
            scope.object.position.copy( scope.position0 );
            scope.object.zoom = scope.zoom0;
    
            scope.object.updateProjectionMatrix();
            scope.dispatchEvent( changeEvent );
    
            scope.update();
    
            state = STATE.NONE;
    
        };
    
        // this method is exposed, but perhaps it would be better if we can make it private...
        this.update = function () {
    
            var offset = new THREE.Vector3();
    
            // so camera.up is the orbit axis
            var quat = new THREE.Quaternion().setFromUnitVectors( object.up, new THREE.Vector3( 0, 1, 0 ) );
            var quatInverse = quat.clone().inverse();
    
            var lastPosition = new THREE.Vector3();
            var lastQuaternion = new THREE.Quaternion();
    
            return function update() {
    
                var position = scope.object.position;
    
                offset.copy( position ).sub( scope.target );
    
                // rotate offset to "y-axis-is-up" space
                offset.applyQuaternion( quat );
    
                // angle from z-axis around y-axis
                spherical.setFromVector3( offset );
    
                if ( scope.autoRotate && state === STATE.NONE ) {
    
                    rotateLeft( getAutoRotationAngle() );
    
                }
    
                spherical.theta += sphericalDelta.theta;
                spherical.phi += sphericalDelta.phi;
    
                // restrict theta to be between desired limits
                spherical.theta = Math.max( scope.minAzimuthAngle, Math.min( scope.maxAzimuthAngle, spherical.theta ) );
    
                // restrict phi to be between desired limits
                spherical.phi = Math.max( scope.minPolarAngle, Math.min( scope.maxPolarAngle, spherical.phi ) );
    
                spherical.makeSafe();
    
    
                spherical.radius *= scale;
    
                // restrict radius to be between desired limits
                spherical.radius = Math.max( scope.minDistance, Math.min( scope.maxDistance, spherical.radius ) );
    
                // move target to panned location
                scope.target.add( panOffset );
    
                offset.setFromSpherical( spherical );
    
                // rotate offset back to "camera-up-vector-is-up" space
                offset.applyQuaternion( quatInverse );
    
                position.copy( scope.target ).add( offset );
    
                scope.object.lookAt( scope.target );
    
                if ( scope.enableDamping === true ) {
    
                    sphericalDelta.theta *= ( 1 - scope.dampingFactor );
                    sphericalDelta.phi *= ( 1 - scope.dampingFactor );
    
                    panOffset.multiplyScalar( 1 - scope.dampingFactor );
    
                } else {
    
                    sphericalDelta.set( 0, 0, 0 );
    
                    panOffset.set( 0, 0, 0 );
    
                }
    
                scale = 1;
    
                // update condition is:
                // min(camera displacement, camera rotation in radians)^2 > EPS
                // using small-angle approximation cos(x/2) = 1 - x^2 / 8
    
                if ( zoomChanged ||
                    lastPosition.distanceToSquared( scope.object.position ) > EPS ||
                    8 * ( 1 - lastQuaternion.dot( scope.object.quaternion ) ) > EPS ) {
    
                    scope.dispatchEvent( changeEvent );
    
                    lastPosition.copy( scope.object.position );
                    lastQuaternion.copy( scope.object.quaternion );
                    zoomChanged = false;
    
                    return true;
    
                }
    
                return false;
    
            };
    
        }();
    
        this.dispose = function () {
    
            scope.domElement.removeEventListener( 'contextmenu', onContextMenu, false );
            scope.domElement.removeEventListener( 'mousedown', onMouseDown, false );
            scope.domElement.removeEventListener( 'wheel', onMouseWheel, false );
    
            scope.domElement.removeEventListener( 'touchstart', onTouchStart, false );
            scope.domElement.removeEventListener( 'touchend', onTouchEnd, false );
            scope.domElement.removeEventListener( 'touchmove', onTouchMove, false );
    
            document.removeEventListener( 'mousemove', onMouseMove, false );
            document.removeEventListener( 'mouseup', onMouseUp, false );
    
            window.removeEventListener( 'keydown', onKeyDown, false );
    
            //scope.dispatchEvent( { type: 'dispose' } ); // should this be added here?
    
        };
    
        //
        // internals
        //
    
        var scope = this;
    
        var changeEvent = { type: 'change' };
        var startEvent = { type: 'start' };
        var endEvent = { type: 'end' };
    
        var STATE = { NONE: - 1, ROTATE: 0, DOLLY: 1, PAN: 2, TOUCH_ROTATE: 3, TOUCH_DOLLY_PAN: 4 };
    
        var state = STATE.NONE;
    
        var EPS = 0.000001;
    
        // current position in spherical coordinates
        var spherical = new THREE.Spherical();
        var sphericalDelta = new THREE.Spherical();
    
        var scale = 1;
        var panOffset = new THREE.Vector3();
        var zoomChanged = false;
    
        var rotateStart = new THREE.Vector2();
        var rotateEnd = new THREE.Vector2();
        var rotateDelta = new THREE.Vector2();
    
        var panStart = new THREE.Vector2();
        var panEnd = new THREE.Vector2();
        var panDelta = new THREE.Vector2();
    
        var dollyStart = new THREE.Vector2();
        var dollyEnd = new THREE.Vector2();
        var dollyDelta = new THREE.Vector2();
    
        function getAutoRotationAngle() {
    
            return 2 * Math.PI / 60 / 60 * scope.autoRotateSpeed;
    
        }
    
        function getZoomScale() {
    
            return Math.pow( 0.95, scope.zoomSpeed );
    
        }
    
        function rotateLeft( angle ) {
    
            sphericalDelta.theta -= angle;
    
        }
    
        function rotateUp( angle ) {
    
            sphericalDelta.phi -= angle;
    
        }
    
        var panLeft = function () {
    
            var v = new THREE.Vector3();
    
            return function panLeft( distance, objectMatrix ) {
    
                v.setFromMatrixColumn( objectMatrix, 0 ); // get X column of objectMatrix
                v.multiplyScalar( - distance );
    
                panOffset.add( v );
    
            };
    
        }();
    
        var panUp = function () {
    
            var v = new THREE.Vector3();
    
            return function panUp( distance, objectMatrix ) {
    
                if ( scope.screenSpacePanning === true ) {
    
                    v.setFromMatrixColumn( objectMatrix, 1 );
    
                } else {
    
                    v.setFromMatrixColumn( objectMatrix, 0 );
                    v.crossVectors( scope.object.up, v );
    
                }
    
                v.multiplyScalar( distance );
    
                panOffset.add( v );
    
            };
    
        }();
    
        // deltaX and deltaY are in pixels; right and down are positive
        var pan = function () {
    
            var offset = new THREE.Vector3();
    
            return function pan( deltaX, deltaY ) {
    
                var element = scope.domElement === document ? scope.domElement.body : scope.domElement;
    
                if ( scope.object.isPerspectiveCamera ) {
    
                    // perspective
                    var position = scope.object.position;
                    offset.copy( position ).sub( scope.target );
                    var targetDistance = offset.length();
    
                    // half of the fov is center to top of screen
                    targetDistance *= Math.tan( ( scope.object.fov / 2 ) * Math.PI / 180.0 );
    
                    // we use only clientHeight here so aspect ratio does not distort speed
                    panLeft( 2 * deltaX * targetDistance / element.clientHeight, scope.object.matrix );
                    panUp( 2 * deltaY * targetDistance / element.clientHeight, scope.object.matrix );
    
                } else if ( scope.object.isOrthographicCamera ) {
    
                    // orthographic
                    panLeft( deltaX * ( scope.object.right - scope.object.left ) / scope.object.zoom / element.clientWidth, scope.object.matrix );
                    panUp( deltaY * ( scope.object.top - scope.object.bottom ) / scope.object.zoom / element.clientHeight, scope.object.matrix );
    
                } else {
    
                    // camera neither orthographic nor perspective
                    console.warn( 'WARNING: OrbitControls.js encountered an unknown camera type - pan disabled.' );
                    scope.enablePan = false;
    
                }
    
            };
    
        }();
    
        function dollyIn( dollyScale ) {
    
            if ( scope.object.isPerspectiveCamera ) {
    
                scale /= dollyScale;
    
            } else if ( scope.object.isOrthographicCamera ) {
    
                scope.object.zoom = Math.max( scope.minZoom, Math.min( scope.maxZoom, scope.object.zoom * dollyScale ) );
                scope.object.updateProjectionMatrix();
                zoomChanged = true;
    
            } else {
    
                console.warn( 'WARNING: OrbitControls.js encountered an unknown camera type - dolly/zoom disabled.' );
                scope.enableZoom = false;
    
            }
    
        }
    
        function dollyOut( dollyScale ) {
    
            if ( scope.object.isPerspectiveCamera ) {
    
                scale *= dollyScale;
    
            } else if ( scope.object.isOrthographicCamera ) {
    
                scope.object.zoom = Math.max( scope.minZoom, Math.min( scope.maxZoom, scope.object.zoom / dollyScale ) );
                scope.object.updateProjectionMatrix();
                zoomChanged = true;
    
            } else {
    
                console.warn( 'WARNING: OrbitControls.js encountered an unknown camera type - dolly/zoom disabled.' );
                scope.enableZoom = false;
    
            }
    
        }
    
        //
        // event callbacks - update the object state
        //
    
        function handleMouseDownRotate( event ) {
    
            //console.log( 'handleMouseDownRotate' );
    
            rotateStart.set( event.clientX, event.clientY );
    
        }
    
        function handleMouseDownDolly( event ) {
    
            //console.log( 'handleMouseDownDolly' );
    
            dollyStart.set( event.clientX, event.clientY );
    
        }
    
        function handleMouseDownPan( event ) {
    
            //console.log( 'handleMouseDownPan' );
    
            panStart.set( event.clientX, event.clientY );
    
        }
    
        function handleMouseMoveRotate( event ) {
    
            //console.log( 'handleMouseMoveRotate' );
    
            rotateEnd.set( event.clientX, event.clientY );
    
            rotateDelta.subVectors( rotateEnd, rotateStart ).multiplyScalar( scope.rotateSpeed );
    
            var element = scope.domElement === document ? scope.domElement.body : scope.domElement;
    
            // rotating across whole screen goes 360 degrees around
            rotateLeft( 2 * Math.PI * rotateDelta.x / element.clientWidth );
    
            // rotating up and down along whole screen attempts to go 360, but limited to 180
            rotateUp( 2 * Math.PI * rotateDelta.y / element.clientHeight );
    
            rotateStart.copy( rotateEnd );
    
            scope.update();
    
        }
    
        function handleMouseMoveDolly( event ) {
    
            //console.log( 'handleMouseMoveDolly' );
    
            dollyEnd.set( event.clientX, event.clientY );
    
            dollyDelta.subVectors( dollyEnd, dollyStart );
    
            if ( dollyDelta.y > 0 ) {
    
                dollyIn( getZoomScale() );
    
            } else if ( dollyDelta.y < 0 ) {
    
                dollyOut( getZoomScale() );
    
            }
    
            dollyStart.copy( dollyEnd );
    
            scope.update();
    
        }
    
        function handleMouseMovePan( event ) {
    
            //console.log( 'handleMouseMovePan' );
    
            panEnd.set( event.clientX, event.clientY );
    
            panDelta.subVectors( panEnd, panStart ).multiplyScalar( scope.panSpeed );
    
            pan( panDelta.x, panDelta.y );
    
            panStart.copy( panEnd );
    
            scope.update();
    
        }
    
        function handleMouseUp( event ) {
    
            // console.log( 'handleMouseUp' );
    
        }
    
        function handleMouseWheel( event ) {
    
            // console.log( 'handleMouseWheel' );
    
            if ( event.deltaY < 0 ) {
    
                dollyOut( getZoomScale() );
    
            } else if ( event.deltaY > 0 ) {
    
                dollyIn( getZoomScale() );
    
            }
    
            scope.update();
    
        }
    
        function handleKeyDown( event ) {
    
            //console.log( 'handleKeyDown' );
    
            switch ( event.keyCode ) {
    
                case scope.keys.UP:
                    pan( 0, scope.keyPanSpeed );
                    scope.update();
                    break;
    
                case scope.keys.BOTTOM:
                    pan( 0, - scope.keyPanSpeed );
                    scope.update();
                    break;
    
                case scope.keys.LEFT:
                    pan( scope.keyPanSpeed, 0 );
                    scope.update();
                    break;
    
                case scope.keys.RIGHT:
                    pan( - scope.keyPanSpeed, 0 );
                    scope.update();
                    break;
    
            }
    
        }
    
        function handleTouchStartRotate( event ) {
    
            //console.log( 'handleTouchStartRotate' );
    
            rotateStart.set( event.touches[ 0 ].pageX, event.touches[ 0 ].pageY );
    
        }
    
        function handleTouchStartDollyPan( event ) {
    
            //console.log( 'handleTouchStartDollyPan' );
    
            if ( scope.enableZoom ) {
    
                var dx = event.touches[ 0 ].pageX - event.touches[ 1 ].pageX;
                var dy = event.touches[ 0 ].pageY - event.touches[ 1 ].pageY;
    
                var distance = Math.sqrt( dx * dx + dy * dy );
    
                dollyStart.set( 0, distance );
    
            }
    
            if ( scope.enablePan ) {
    
                var x = 0.5 * ( event.touches[ 0 ].pageX + event.touches[ 1 ].pageX );
                var y = 0.5 * ( event.touches[ 0 ].pageY + event.touches[ 1 ].pageY );
    
                panStart.set( x, y );
    
            }
    
        }
    
        function handleTouchMoveRotate( event ) {
    
            //console.log( 'handleTouchMoveRotate' );
    
            rotateEnd.set( event.touches[ 0 ].pageX, event.touches[ 0 ].pageY );
    
            rotateDelta.subVectors( rotateEnd, rotateStart ).multiplyScalar( scope.rotateSpeed );
    
            var element = scope.domElement === document ? scope.domElement.body : scope.domElement;
    
            // rotating across whole screen goes 360 degrees around
            rotateLeft( 2 * Math.PI * rotateDelta.x / element.clientWidth );
    
            // rotating up and down along whole screen attempts to go 360, but limited to 180
            rotateUp( 2 * Math.PI * rotateDelta.y / element.clientHeight );
    
            rotateStart.copy( rotateEnd );
    
            scope.update();
    
        }
    
        function handleTouchMoveDollyPan( event ) {
    
            //console.log( 'handleTouchMoveDollyPan' );
    
            if ( scope.enableZoom ) {
    
                var dx = event.touches[ 0 ].pageX - event.touches[ 1 ].pageX;
                var dy = event.touches[ 0 ].pageY - event.touches[ 1 ].pageY;
    
                var distance = Math.sqrt( dx * dx + dy * dy );
    
                dollyEnd.set( 0, distance );
    
                dollyDelta.set( 0, Math.pow( dollyEnd.y / dollyStart.y, scope.zoomSpeed ) );
    
                dollyIn( dollyDelta.y );
    
                dollyStart.copy( dollyEnd );
    
            }
    
            if ( scope.enablePan ) {
    
                var x = 0.5 * ( event.touches[ 0 ].pageX + event.touches[ 1 ].pageX );
                var y = 0.5 * ( event.touches[ 0 ].pageY + event.touches[ 1 ].pageY );
    
                panEnd.set( x, y );
    
                panDelta.subVectors( panEnd, panStart ).multiplyScalar( scope.panSpeed );
    
                pan( panDelta.x, panDelta.y );
    
                panStart.copy( panEnd );
    
            }
    
            scope.update();
    
        }
    
        function handleTouchEnd( event ) {
    
            //console.log( 'handleTouchEnd' );
    
        }
    
        //
        // event handlers - FSM: listen for events and reset state
        //
    
        function onMouseDown( event ) {
    
            if ( scope.enabled === false ) return;
    
            event.preventDefault();
    
            switch ( event.button ) {
    
                case scope.mouseButtons.ORBIT:
    
                    if ( scope.enableRotate === false ) return;
    
                    handleMouseDownRotate( event );
    
                    state = STATE.ROTATE;
    
                    break;
    
                case scope.mouseButtons.ZOOM:
    
                    if ( scope.enableZoom === false ) return;
    
                    handleMouseDownDolly( event );
    
                    state = STATE.DOLLY;
    
                    break;
    
                case scope.mouseButtons.PAN:
    
                    if ( scope.enablePan === false ) return;
    
                    handleMouseDownPan( event );
    
                    state = STATE.PAN;
    
                    break;
    
            }
    
            if ( state !== STATE.NONE ) {
    
                document.addEventListener( 'mousemove', onMouseMove, false );
                document.addEventListener( 'mouseup', onMouseUp, false );
    
                scope.dispatchEvent( startEvent );
    
            }
    
        }
    
        function onMouseMove( event ) {
    
            if ( scope.enabled === false ) return;
    
            event.preventDefault();
    
            switch ( state ) {
    
                case STATE.ROTATE:
    
                    if ( scope.enableRotate === false ) return;
    
                    handleMouseMoveRotate( event );
    
                    break;
    
                case STATE.DOLLY:
    
                    if ( scope.enableZoom === false ) return;
    
                    handleMouseMoveDolly( event );
    
                    break;
    
                case STATE.PAN:
    
                    if ( scope.enablePan === false ) return;
    
                    handleMouseMovePan( event );
    
                    break;
    
            }
    
        }
    
        function onMouseUp( event ) {
    
            if ( scope.enabled === false ) return;
    
            handleMouseUp( event );
    
            document.removeEventListener( 'mousemove', onMouseMove, false );
            document.removeEventListener( 'mouseup', onMouseUp, false );
    
            scope.dispatchEvent( endEvent );
    
            state = STATE.NONE;
    
        }
    
        function onMouseWheel( event ) {
    
            if ( scope.enabled === false || scope.enableZoom === false || ( state !== STATE.NONE && state !== STATE.ROTATE ) ) return;
    
            event.preventDefault();
            event.stopPropagation();
    
            scope.dispatchEvent( startEvent );
    
            handleMouseWheel( event );
    
            scope.dispatchEvent( endEvent );
    
        }
    
        function onKeyDown( event ) {
    
            if ( scope.enabled === false || scope.enableKeys === false || scope.enablePan === false ) return;
    
            handleKeyDown( event );
    
        }
    
        function onTouchStart( event ) {
    
            if ( scope.enabled === false ) return;
    
            event.preventDefault();
    
            switch ( event.touches.length ) {
    
                case 1:	// one-fingered touch: rotate
    
                    if ( scope.enableRotate === false ) return;
    
                    handleTouchStartRotate( event );
    
                    state = STATE.TOUCH_ROTATE;
    
                    break;
    
                case 2:	// two-fingered touch: dolly-pan
    
                    if ( scope.enableZoom === false && scope.enablePan === false ) return;
    
                    handleTouchStartDollyPan( event );
    
                    state = STATE.TOUCH_DOLLY_PAN;
    
                    break;
    
                default:
    
                    state = STATE.NONE;
    
            }
    
            if ( state !== STATE.NONE ) {
    
                scope.dispatchEvent( startEvent );
    
            }
    
        }
    
        function onTouchMove( event ) {
    
            if ( scope.enabled === false ) return;
    
            event.preventDefault();
            event.stopPropagation();
    
            switch ( event.touches.length ) {
    
                case 1: // one-fingered touch: rotate
    
                    if ( scope.enableRotate === false ) return;
                    if ( state !== STATE.TOUCH_ROTATE ) return; // is this needed?
    
                    handleTouchMoveRotate( event );
    
                    break;
    
                case 2: // two-fingered touch: dolly-pan
    
                    if ( scope.enableZoom === false && scope.enablePan === false ) return;
                    if ( state !== STATE.TOUCH_DOLLY_PAN ) return; // is this needed?
    
                    handleTouchMoveDollyPan( event );
    
                    break;
    
                default:
    
                    state = STATE.NONE;
    
            }
    
        }
    
        function onTouchEnd( event ) {
    
            if ( scope.enabled === false ) return;
    
            handleTouchEnd( event );
    
            scope.dispatchEvent( endEvent );
    
            state = STATE.NONE;
    
        }
    
        function onContextMenu( event ) {
    
            if ( scope.enabled === false ) return;
    
            event.preventDefault();
    
        }
    
        //
    
        scope.domElement.addEventListener( 'contextmenu', onContextMenu, false );
    
        scope.domElement.addEventListener( 'mousedown', onMouseDown, false );
        scope.domElement.addEventListener( 'wheel', onMouseWheel, false );
    
        scope.domElement.addEventListener( 'touchstart', onTouchStart, false );
        scope.domElement.addEventListener( 'touchend', onTouchEnd, false );
        scope.domElement.addEventListener( 'touchmove', onTouchMove, false );
    
        window.addEventListener( 'keydown', onKeyDown, false );
    
        // force an update at start
    
        this.update();
    
    };
    
    THREE.OrbitControls.prototype = Object.create( THREE.EventDispatcher.prototype );
    THREE.OrbitControls.prototype.constructor = THREE.OrbitControls;
    
    Object.defineProperties( THREE.OrbitControls.prototype, {
    
        center: {
    
            get: function () {
    
                console.warn( 'THREE.OrbitControls: .center has been renamed to .target' );
                return this.target;
    
            }
    
        },
    
        // backward compatibility
    
        noZoom: {
    
            get: function () {
    
                console.warn( 'THREE.OrbitControls: .noZoom has been deprecated. Use .enableZoom instead.' );
                return ! this.enableZoom;
    
            },
    
            set: function ( value ) {
    
                console.warn( 'THREE.OrbitControls: .noZoom has been deprecated. Use .enableZoom instead.' );
                this.enableZoom = ! value;
    
            }
    
        },
    
        noRotate: {
    
            get: function () {
    
                console.warn( 'THREE.OrbitControls: .noRotate has been deprecated. Use .enableRotate instead.' );
                return ! this.enableRotate;
    
            },
    
            set: function ( value ) {
    
                console.warn( 'THREE.OrbitControls: .noRotate has been deprecated. Use .enableRotate instead.' );
                this.enableRotate = ! value;
    
            }
    
        },
    
        noPan: {
    
            get: function () {
    
                console.warn( 'THREE.OrbitControls: .noPan has been deprecated. Use .enablePan instead.' );
                return ! this.enablePan;
    
            },
    
            set: function ( value ) {
    
                console.warn( 'THREE.OrbitControls: .noPan has been deprecated. Use .enablePan instead.' );
                this.enablePan = ! value;
    
            }
    
        },
    
        noKeys: {
    
            get: function () {
    
                console.warn( 'THREE.OrbitControls: .noKeys has been deprecated. Use .enableKeys instead.' );
                return ! this.enableKeys;
    
            },
    
            set: function ( value ) {
    
                console.warn( 'THREE.OrbitControls: .noKeys has been deprecated. Use .enableKeys instead.' );
                this.enableKeys = ! value;
    
            }
    
        },
    
        staticMoving: {
    
            get: function () {
    
                console.warn( 'THREE.OrbitControls: .staticMoving has been deprecated. Use .enableDamping instead.' );
                return ! this.enableDamping;
    
            },
    
            set: function ( value ) {
    
                console.warn( 'THREE.OrbitControls: .staticMoving has been deprecated. Use .enableDamping instead.' );
                this.enableDamping = ! value;
    
            }
    
        },
    
        dynamicDampingFactor: {
    
            get: function () {
    
                console.warn( 'THREE.OrbitControls: .dynamicDampingFactor has been renamed. Use .dampingFactor instead.' );
                return this.dampingFactor;
    
            },
    
            set: function ( value ) {
    
                console.warn( 'THREE.OrbitControls: .dynamicDampingFactor has been renamed. Use .dampingFactor instead.' );
                this.dampingFactor = value;
    
            }
    
        }
    
    } );